1. Field of the Invention
The present invention relates to electrical switches, and in particular, pertains to a novel rotary-actuated electrical switch which is utilized for electrical current and especially alternating current circuits.
The utilization of lever-operated switches for electrical circuits, especially but not limited to alternating current circuits, is well known in the technology, and wherein such switches provide convenient and easily operated devices for the manual switching of electrical current circuits. A considerable number of electrical switches, particularly lever-operated switches which are employed in connection with alternating current circuits have been and are presently employed in industry and are the subject matter of numerous U.S. patents. Such switches generally have the movement of a lever acting directly on a plunger or similar member which, in turn, acts upon electrical contacts to selectively open or close the latter. Other types of electrical switches which are lever-operated incorporate mechanisms in which the lever acts upon a link which pivots in a manner to cause a switch element to effectuate the opening or closing of the electrical contacts. In instances where high electrical currents are interrupted by such switch contacts upon separation between the latter, it is possible that an electrical arc may be formed at the contact surfaces, which may result in the generation of heat and hot gases, thereby necessitating that protective measures be taken to shield the remainder of the switch structure from potentially destructive effects resulting from the generated heat and gases.
2. Discussion of the Prior Art
More recently, lever-operated electrical switches have been developed which are especially adapted for utilization in alternating current circuits, and which to a considerable extent, have improved upon overcoming the shortcomings and drawbacks encountered with earlier similar types of lever-operated electrical switches. An electrical switch of that type which is used for the switching of alternating current circuits employs a lever which is pivoted between an OFF and an ON position, and wherein the lever includes structure connected to a pivotable link and pin assembly operating in opposition to the biasing force of lift springs of a lifter is adapted to be vertically displaced between a contact opening and a contact closing position responsive to the actuation or "throw" of the lever in a generally arcuate motion. For example, an electrical lever-operated switch of that type is known from the disclosure of U.S. Pat. No. 4,400,603 to Wiley; whereas a somewhat similar "on position" motor starting switch is also known and currently manufactured by Bryant Electric Division of Hubbell Corporation, Milford, Conn.
Although the lever-operated electrical switches disclosed in the above-mentioned U.S. patent and those currently being manufactured by Bryant utilize contact-actuating lifters which are acted upon by lifter springs, and wherein the ON and OFF positions between movable and stationary electrical contacts are controlled through the intermediary of a lever handle, the pivoting displacement of which oscillates a link and pin assembly tending to either push the lifter downwardly so as to force a movable brush and contact assembly into a contact-open position, or alternatively to permit the lifter to be urged upwardly responsive to the lifter springs so as to enable the movable and stationary electrical contacts to come into current-conducting engagement.
The above-mentioned lever-operated electrical switches may, at times, be subject to "teasing" action during the movement of the lever between the ON and OFF switching positions, and the manual over- the-center actuation of the lever, upon occasion, causes the switch to be inadvertently hung-up or located in a so-called "tease" position in which the contacts are not quite separated or closed, so as to conceivably cause electrical arcing to take place between the contacts with resultant generation of heat and gases.